/*
 * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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/*
 * (C) Copyright IBM Corp. 2005, All Rights Reserved.
 */
package java.awt.font;

import java.awt.geom.Point2D;

/**
 * LayoutPath provides a mapping between locations relative to the
 * baseline and points in user space.  Locations consist of an advance
 * along the baseline, and an offset perpendicular to the baseline at
 * the advance.  Positive values along the perpendicular are in the
 * direction that is 90 degrees clockwise from the baseline vector.
 * Locations are represented as a <code>Point2D</code>, where x is the advance and
 * y is the offset.
 *
 * @since 1.6
 */
public abstract class LayoutPath {

  /**
   * Convert a point in user space to a location relative to the
   * path. The location is chosen so as to minimize the distance
   * from the point to the path (e.g., the magnitude of the offset
   * will be smallest).  If there is more than one such location,
   * the location with the smallest advance is chosen.
   *
   * @param point the point to convert.  If it is not the same object as location, point will remain
   * unmodified by this call.
   * @param location a <code>Point2D</code> to hold the returned location. It can be the same object
   * as point.
   * @return true if the point is associated with the portion of the path preceding the location,
   * false if it is associated with the portion following.  The default, if the location is not at a
   * break or sharp bend in the path, is to return true.
   * @throws NullPointerException if point or location is null
   * @since 1.6
   */
  public abstract boolean pointToPath(Point2D point, Point2D location);

  /**
   * Convert a location relative to the path to a point in user
   * coordinates.  The path might bend abruptly or be disjoint at
   * the location's advance.  If this is the case, the value of
   * 'preceding' is used to disambiguate the portion of the path
   * whose location and slope is to be used to interpret the offset.
   *
   * @param location a <code>Point2D</code> representing the advance (in x) and offset (in y) of a
   * location relative to the path.  If location is not the same object as point, location will
   * remain unmodified by this call.
   * @param preceding if true, the portion preceding the advance should be used, if false the
   * portion after should be used. This has no effect if the path does not break or bend sharply at
   * the advance.
   * @param point a <code>Point2D</code> to hold the returned point.  It can be the same object as
   * location.
   * @throws NullPointerException if location or point is null
   * @since 1.6
   */
  public abstract void pathToPoint(Point2D location, boolean preceding,
      Point2D point);
}
